More Power to get away from the traffic light?

[Rano]

Hi

yes I am sure I´m not the first to ask (but maybe the earliest?).
Ok, my Brammo is just 2 days old, and I drove about 20km (in the city of Vienna).

A really nice bike.

To make it a really great bike, is there any possibility to give it at low speed a bit more acceleration power? Is there a kind of current limitation - it would be OK for me if the range decreases in case of an increase of acceleration...

Many Thanks!

Rano

 

[BrammoBrian]

Rano,

Congratulations on your Enertia Plus.  As you've mentioned, it's a great bike for the city and I hope you enjoy it more as you are able to ride more. 

To answer your question about the "off-the-line" acceleration:

The Enertia Plus is fitted with the Sevcon Gen 4 Size 2 motor controller, which has a maximum boost current that is ultimately the limiting factor.  We try to use as much current as possible and run a relatively large rear sprocket to help.  Increasing this performance, would ultimately lead to lower average range, although it sounds like this is a trade-off you'd be willing to make.

Cold weather (I see it's hovering around 0 degrees C in Vienna right now) will certainly affect the performance of the bike as well as it decreases the ability of the battery to provide high current.  You'll notice a slight increase in performance and driving range when it starts to warm in the spring time.

The best short term option would be to increase the rear sprocket size by a couple of teeth to gain some mechanical advantage and rear wheel torque, but sacrifice a bit of top speed. Your speedometer would also be off slightly as the speed reading comes from the motor controller based on motor speed rather than a rear wheel speed sensor.  Brammo does not currently have an option like this, so it would require having the sprocket fabricated yourself. 

Longer term, we can look at other options, like moving up to the Size 4 motor controller, which would provide more peak current for acceleration.  Thank you for the feedback, we would like to continue to work to make the Enertia a "really great bike"!   
 

[FrankH]

Thanks for your explanation Brian, I have the same feeling about the Enertia+'s acceleration.
I drove mine last thursday in similar conditions (temperatures just above freezing) so I hope that higher temperatures will make a difference.
It also felt like it was limited to 110km/h (68mph). Is that also a limitation of the motor controller? 110 is still more than the advertised max speed so I'm not disappointed there.
More off-the-line acceleration would be really nice to have though. How big an impact would upgrading to another motor controller have? Could that ever be an option on current Enertia+'s or would that only be possible on a future version?

I was actually hoping that this would be modifiable through software, that you limited the Enertia's acceleration to prevent people from accidental wheelies (because the torque on electric motors is supposed to be so strong). But that dream is over now, I guess.

Frank

[Rano]

Hi Brian, thanks for the explanation.

Hmmm... to encrease the mechanical torque of course it would be an opporunity to increase the right now "relatively large rear sprocket". What is it right now? 72 or 74? If in increase I fear that in right turns it might scratch the road

Would it be possible to decrease the sprocket at the engine side, or is it already the smallest possible size?

Perfect would be a decrease by factor 0.62, in this case I could use the "miles" and not the "kilometers" at the speedometer. [this has been a joke]

As Frank asked, is an upgrade to a Gen4 Size 4 possible, by me (have some skills here) or by my dealer, and would I also need an upgrade of the software?

One question to get a better understanding
- Is it the same maximal current off-the-line as at 30 mph?
- I am asking as the power displays shows about 5 kW at the beginning of acceleration and limits later at 13kW
- I am not so good at mechanics, Power is Force*Speed (Momentum*Speed), which I would understand, but also Current*Voltage, which should be a constant at the maximum? Here I am a bit confused...

Now its getting snowy... does Brammo sell a tuning set "snowmobile"?
Rano
 

[Rano]

Just took a look at he Sevcon Gen4 - Seems to be a central ECU of the bike, not just a simple inverter. Hmmm major surgery...

But 275A peek current should be enough at Size 2?

[FrankH]

Hey Rano,

you said you drove your Enertia through Vienna, does that mean you got the paperwork done? I think I had the same issue you had with the CoC not being recognised in the authorities' system. If it's fixed in Austria it should be ok all over Europe now. That would be good news!

Or was that a one day permit to drive it to the testing station like I had?

[Rano]

Hi Frank,

I got a "real" permission, my dealer sent it to the authorities on monday, on wednesday it was not finished, but on friday everything was fine. Thus, it is fixed here. And I always thougt that our government is slow...

Hopefully good news for you.

[BrammoBrian]

Hi Brian, thanks for the explanation.

Hmmm... to encrease the mechanical torque of course it would be an opporunity to increase the right now "relatively large rear sprocket". What is it right now? 72 or 74? If in increase I fear that in right turns it might scratch the road

Would it be possible to decrease the sprocket at the engine side, or is it already the smallest possible size?

As Frank asked, is an upgrade to a Gen4 Size 4 possible, by me (have some skills here) or by my dealer, and would I also need an upgrade of the software?

One question to get a better understanding
- Is it the same maximal current off-the-line as at 30 mph?
- I am asking as the power displays shows about 5 kW at the beginning of acceleration and limits later at 13kW
- I am not so good at mechanics, Power is Force*Speed (Momentum*Speed), which I would understand, but also Current*Voltage, which should be a constant at the maximum? Here I am a bit confused...

I don't recall off the top of my head what rear sprocket size we are running on the Enertia Plus, but it is most likely stamped in the side of the sprocket somewhere.  I agree that it is already quite large and going larger would most likely decrease chain life.  It is not possible to go any smaller on the motor counter-shaft sprocket, sorry.   

The Sevcon Size 4 could only be made to fit if you re-located the 12V DC-DC converter, so I cannot recommend attempting this. It would also require some fairly extensive software tuning that would be difficult to acheive without the full support of the OEM (i.e. Brammo).  I will take your request for an upgrade path to heart as we make future plans.  Our desire (although it is not always possible) is to meet the requests of our customers. 

Power is torque x rpm, so it is reasonable that the power displayed on the dash is lower on initial acceleration than when up to speed.  5kW is about right for 50Nm at 1000rpm.

You are correct that the maximum speed is limited by software.  I'm glad that you find this speed sufficient for your usage. 

I think you are now able to experience the trade-off of a direct-drive system versus a transmission.  The direct drive is very smooth and has good power/acceleration at higher rpm, but lacks the "off-the-line" performance that is possible with multiple ratios in a gearbox.  You should always ask/calculate rear wheel torque, which is far more important than torque at the motor.  This will tell you your accelerative force available. 

[protomech]

FrankH & Arnman:

What is the approximate 0-60 mph or 0-100 km/h time for the Enertia Plus?

All true about transmission vs direct drive, but there's a second option, which we will see if there's a comparison review between the Enertia Plus and the smaller-battery 2013 Zero XU. I believe the Zero XU also runs the Sevcon G8018 .. same controller as the Enertia Plus I think.

[BrammoBrian]

All true about transmission vs direct drive, but there's a second option...

Do tell?

[protomech]

Bigger motor

[FrankH]

What is the approximate 0-60 mph or 0-100 km/h time for the Enertia Plus?

I can't answer that yet as my Plus is waiting for a licence plate. Not allowed to drive on the road until then and my garden's not big enough to reach 100km/h

[Rano]

I will make an acceleration test today... Just got an app.

[Rano]

Puhhh its freezy cold... 7 degrees and stormy.
My app did not work but it has been about 16 seconds to reach 100km/h

The fan did not stop running, although the temp did not exceed 65°C

[protomech]

27F / -3C here today. Brrrrrrrr.

16s 0-60 sounds about as fast as the Enertia Classic.